Simple write-once-read-many-times memory device based on a carbon sphere-poly(vinylphenol) composite

We report on the electrical properties of a thin film of carbon spheres and cross-linked poly(4-vinylphenol) composites, sandwiched between an Al bottom contact and a Au or Al top contact. These simple sandwich structure memory devices show write-once-read-many-times (WORM) characteristics with an ON/OFF current ratio of 108 at 1 V bias when Au is used as top contact and the write operation corresponding to an OFF/ON transition can be made at low voltages, of ca. 2 V.